The U.S. power grid will undergo an unprecedented change in the energy sources that power it over the next 10 years, including significant increases in wind and solar power generation, according to the North American Electric Reliability Corporation (NERC). NERC, which is responsible for the reliability of the power grid, released its 2010 Long-Term Reliability Assessment on October 20. The report looks ahead 10 years, dividing future energy resources into "planned" resources—those anticipated to become available in the next decade—and "conceptual" resources, which are in early stages of development and are less certain.

According to the report, 180,000 megawatts (MW) of wind and solar resources—53,000 planned MW and 126,000 conceptual MW—will be added in the contiguous United States and Canada by 2019. The total includes more than 165,000 MW of new wind power capacity, although only 24,000 MW of wind power are expected to be available during times of peak power demand. As a result, fossil-fueled, nuclear, and hydropower generation are projected to provide more than 90% of the capacity necessary to meet peak demand in North America by 2019. But within the coming year, natural gas is expected to replace coal as the leading fuel for peak capacity, and that trend is expected to continue with nearly 60,000 MW of new gas-fired generation capacity expected by 2019.

Meanwhile, the economic recession has caused a significant reduction in projected long-term energy use across North America. Combined with decreases in demand during the recession, the effect has been to defer the projected growth in peak demand by about four years relative to projections made in 2008. Peak demand in the United States is now projected to grow at only 1.3% per year, while net electrical energy needs are projected to grow at an annual rate of 1.6%. In the next decade, energy efficiency efforts in the United States and Canada are expected to reduce the growth in electrical demand by about 10,300 MW. Meanwhile, demand response is expected to grow from 30,000 MW in 2010 to about 40,000 MW in 2019. In the United States alone, energy efficiency and demand response are expected to reduce projected peak demands by 40,000 MW by 2019. See the NERC press release and report.